Concrete forms



SePt- Y14, 1965 s. G. JOHNSON ETAL 3,205,552

CONCRETE FORMS Original Filed Oct. 5l, 1961 4 Sheets-Sheet 1 ITI Sept 14, 1955 s. G. JoHNsoN ETAL 3,205,552

CONCRETE FORMS original Filed oct. 31. 1961 4 Sheets-Sheet 2 wn/0@ W Km2 Bv SePt- 14, 1965 s. G. JoHNsoN ETAL 3,205,552

CONCRETE FORMS Original Filed Oct. 31. 1961 4 Sheets-Sheet 3 IELE=E .5m/VL y 6, JOHNSON Sept- 14, 1965 s. G. JoHNsoN ETAL 3,205,552

CONCRETE FORMS United States Patent O 3,205,552 CUNCRETE FGRMS Stanley G. .iohnsonJ 2S536 Elmwood, Garden City, Mich.,

and Arthur W. Kurtz, Detroit, Mich.; said Kurtz assignor to said .lohnson Original application Oct. 31, 1961, Ser. No. 152,707. Divided and this application Oct. 10, 1963, Ser. No.

1 Claim. (Cl. Z5-130) The Ipresent invention is a divisional application of our oopending lapplication Serial Number 152,707, filed October 31, 1961, and contains the same general subject matter as -ou-r application Serial Number 49,924, tiled August 16, 1960 (now abandoned).

The invention relates to improvements in expansible concrete forms `of the type used in the casting of generaly hollow concrete products of rectangular conliguration, such as septic tanks, burial Vaults and the like. While particular reference yhas been made to septic tanks and burial vaults, it `must be lunderstood that this disclosure is made for the purpose -of description, since the principles involved may be used `on many other si-milar type rectangular type concrete products.

It has been well established throughout the years that it is advantageous to cast hollow concrete products in an inverted position, due to the simplified pouring technique which can be employed. The concrete form of the -present invention is poured so that the casting is formed in the inverted position. The natural lforce of gravity acts upon the wet con-crete to lill the form. In addition to the gravitational forces, the form is also subjected to external vibration, thereby eliminating the necessity of accurately directing the Wet concrete between the sidewalls of the forms. The use of external vibration also insures the production of a finished casting that is not porous.

The .present invention employs the use of a two part concrete form, wherein the inner form is retractable while the outer form is -of two part construction and is readily expansible in two directions, so as to permit quick and easy removal of a finished casting. Although the release and removal -of the outer for-m is a relatively simple matter, yconsiderable difficulty has been encountered in other Aforms because of the lack of draft in the finis-hed product.

This application is directed to the expansible outer form and it is `a primary object of this invention to provide an expansible concrete form which will readily release a finished casting, without employing draft on either of the .surfaces of the castings.

Another `object of the invention is the provision of a two part concrete -form wherein the outer expansible form can be readily released without necessity of releasing the inner form, thereby permitting the manufacture of a double wal-led structure which is completely waterproof,

whereby a first thin wall casting is fonmed after which the outer form is released so as to permit the application of a waterproofing material, which operation is followed by the rca-positioning of the outer form whereby a second pour is made to bring the wall thickness up to the desired thickness.

Still another object of the present invention is the provision of a relatively simple concrete foam which is not only durable, but can be readily fabricated, using modern trnass production methods.

These and other objects can be accomplished by the provision of a generally rectangular casting device having a retractable inner form and an expansible outer form, the outer form being of generally symmetrical configuration and mounted `on a substantially flat base member in uniform spaced relationship to said inner retractable form; said outer fonm of two part construction and separable on two diametrically opposed corners; each part of 3,205,552 Patentedy Sept. 14, 1965 ICC said expansible form being of generally L-'shaped configuration; a flange substantially circumscribing the outside of each of said L-shaped form sections; a plurality of spaced openings in said ange along the sides and ends of said form sections; a plurality lof dowel pins extending upwardly from said flat 'base member in alignment with said openings, said dowel pins adapted to cooperate with the openings in said ange member, to align said outer form with the base and said inner form; a right angie member ysecured fbetween each of the open corners of said L-shaped form sections; a plurality of horizontal slots in each of said right angle .corner members, said horizontal slots -cooperable with a similar number of studs which extend from each of said form members to effect accurate yalignment thereof; `and clamping means for clamping said form members together when assembled, which clamping means include means for equally expanding said corner members to effect the release of a finished casting, when same has been removed from the retractable inner form which is retractable.

Other obje-cts -of this invention will appear in the following description and appended claim, reference being had to the accompanying drawings forming a part of this specification, wherein like reference characters designate correspond-ing parts in the several views.

In the drawings:

FIGURE 1 illustrates a plan view .of a concrete form which embodies the present invention.

:FIGURE 2 is also a plan View of the concrete form shown in `FIGURE 1, with the top removed.

FIGURE 3 is an elevational View of the concrete form illustrated in FIGURE 1. l

FIGURE 4 is an elevational view similar to that of yFGURE 3, with the outer expansi-ble form broken away.

FIGURE 5 is a cross sectional View taken substantially along the plane 5 5 of yFIGURE 2 with the inner form in the closed position.

FIGURE 6 is an elevational view of the present invention with the outer form broken away and with the inner `form shown in the inoperative position.

FIGURE 7 is an elevational view of the concrete form with both the outer form and the inner form broken away, with the inner form illustrated in the inoperative or open position.

FIGURE 8 is a cross section of a corner structure with the outer for-m shown in plan view.

FIGURE 9 is an elevational view of a concrete form which illustrates a modified outer form.

FIGURE 10 is a cross section taken along the plane 10-10 of FIGURE 9.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

Referring to FIGURE l, this drawing illustrates a plan view of a two part concrete form 10, which embodies the present invention. The complete concrete form assembly lt) is mounted on a at, generally rectangular frame or base structure 12. The complete concrete form assembly 10 is made up of two major components, an inner retractable form 30 and an outer form 2.0` which is expansible. i

The base structure 12 is of generally rectangular configuration and has four leg members 13 depending downwardly therefrom, one leg is secured to each of the four corners thereof. The body or central portion of the bas-e 12 is generally open, while the perimeter 14 is similar to a picture frame, with the inner edges thereof being deformed downwardly. This deformed portion is identified by numeral 16 and provides a sealing lip on the finished concrete casting. A cast concrete cover is positioned thereon. The outer edge of the base frame 12 is generally fiat and has a plurality of upwardly extending dowelpins 18 located thereon. Each of the dowel pins 18 is adapted to engage a plurality of aligned openings 19 in aV flange 26 which extends along the lower edges of the outside of side and end members 21, 21a, 22 and 22a. The tiange 26 substantially circumscribes the outer expansible form and is ingenerally parallel relationship to the base frame 12. The elevational view in FIGURE 3 best discloses this structure.

Each section 21, 21a, 22 and 22a of the outer expansible form is of generally L-shaped configuration and when v joined together, forms a rectangular, hollow box like construction. One vertical edge of each of said L-shaped outer form members is provided with a short right angle tiange 23, adapted to lie in generally parallel relationship with the vertical side of the opposite form member which is adjacent thereto. Each of the iianged portions has two or more horizontal slots 24 in each face thereof, into which threaded stud members 25, secured to the body proper, are positioned to provide a means for locating andpositioning each of the outer form sections.

Clamping means (not shown) are provided to maintain each of the two form members in positive fixed relationship. The upper horizontal edge of each of said L-shaped form members 21 and 22 are'flanged for rigidity. Each of the L-shaped form members have a ange section 26 thereon which is spaced from the lower edge thereon. The iiange section 26 has a plurality of aligned openings 19 therein which are adapted to engage a p lurality of dowel pins 18 which extend upwardly from the base frame 12. Additional clamping means (not shown) are also provided for maintaining the outer expansible form in positive contact with the base frame 12.

In the modified form of the present invention shown in FIGURE 10, the two part expansible form 120 is of the same general construction previously described, however, the flanged corner sections 123 are of slightly different conguration. Each of the corner sections are of W-shaped cross section and are adapted to have mounted thereon, a pair of meshing bevel gears 131 and 132 which are journaled in bearings 134 secured to their respective flanges. The bevel gears 131 and 132 are positioned on threaded shaft members'136 and 138 respectively. A threaded nut 139 is securely afixed to each of the end and side members so that rotation of the shaft members 136 and 138 will cause the two L- shaped expansible form members to separate at a uniform rate. Since the diagonally opposite corners of the form are of the same construction, it will be apparent that each of the corners will be operated in unison to obtain maximum efficiency from this structure. It will also be apparent that the modified corner structure eliminates the necessity of having any additional clamping devices on the corners for holding same in ypre-determined relationship, since the threaded structure positively eliminates any possibility of corner separation in either corner.

The plan view of the present invention illustrated in FIGURE 2 shows the outer form 20 in the operative position. The inner form 30 is also shown in the operative position, while the at top cover 24b has been removed for purposes of illustrating the mechanism contained within said inner form. The linkage mechanism is adapted to simultaneously operate the two sides 32 and 34 which are pivoted on the base 12, as well as the two end members 36 and 38 which are also pivoted on the base frame 12. The corner members 40, 42, 44 and 46 of the inner form are disposed intermediate the side and end members and are Operated in unison with another linkage which is cooperable with vsaid first mentioned linkage.

It will also be noted that two guide posts 48 and 50 are symmetrically positioned on two cross members 52 and S4 respectively, located on the base frame 12. The guide members 48 and 50 locate and position a horizontal actuating bar 60. Each end of the horizontal actuating bar 60 has pivotally secured thereto a pivotal member 68 which is pivotally connected to each of the end members 36 and 38 of the inner form. In addition thereto, a plurality of adjustable pivotal links 72Y are interposed between the side members 32 and 34 and the side of the horizontal actuating bar 60. It will now be readily apparent that as the actuating bar 60 is moved up and down on the guide posts 48 and 50, the pivotal members 63 and the adjustable links 72 will operate to pivot the end members 36` and 38 a-s well as the sides 32 and '34.

Cross members 52 and 54 also have positioned thereon, a rectangular supporting frame Vwhich locates and positions four pivotal'L-shaped links 76, 78, 82 'and 84. The upper ends 96, 98,102 and 104 are secured to four linkages 86, 88, 92 and 94, which in turn are connected to the four right angle corner members 40, 42, 44 and 46 which are pivotal. The sides32 and 34 are pivoted on the base frame 12 with a plurality of hinges 106, while theend members are pivoted to the base frame 12 with a plurality of hinges 108. The right angle corner members 40, 42, 44 and 46 are pivotal about the two vertical edges of each of the side members 32 and 34 on hinges 109.

The operating'means 110 for expanding or retracting the inner form 30 extends transversely across the bottom of the base frame 12 and is operable to cause the various linkages attached therto to operate the sides, ends and corners to expandA or retract said inner form. An arm 114 is secured to the actuating means 110, to which are secured'pivotal links 116, 118, 120 and 122. The respective links are secured to the free ends of the L-shaped links 76, 78, 82 and 84. Links 116 and 118 are secured to the ends of links 76 and 78, while links 120 and 122 are secured to links 82 and 84. Link 124 is pivotally secured to bracket 126 at one end and to the end of arm 114 at the other.

The cover member 240 is of generally rectangular confiiguration and has a pair of downwardly depending hollow sleeves 49 and 51 secured to the central` portion thereof. The hollow sleeve members 49 and 51 are positioned to cooperate and engage the end portion of the guide posts 48 and S0, thereby aligning and positioning. the top cover 240 in proper relationship to the sides, ends and corner members.

The cylindrical extensions on the ends of the expansible outerform 20 are used for transporting the outer form 20 independently or with a casting contained therewithin, from place to place. The extensions 150 are positioned in the central portion of each of the ends 21 and 22.

Operation After the concrete casting has been poured and had time to partially-cure, the single operating handle member 112' is moved to actuate the various linkages contained within the inner form, thereby retracting said inner form. An overhead crane or chain fall is then employed to remove: the outer form 20 and concrete casting, which is frictionally held therein. The form 20 and casting are then rotated on the cylindrical extensions 150 to place the casting in an upright postion. In one instance the clampmg means on each corner is released, thereby allowing the outer form 20 to be expanded to release the casting, while in the other instance the bevel gears on each of two corners are rotated, thereby causing the outer form to expand at a uniform rate and release the casting. Thereafter the outer form is removed from the casting and repositioned on the base frame 12 for a successive, pour.

Having thus described our invention, we claim:

In a concrete form for the manufacture of draft free hollow products using a rectangular outer form, the cornbinaton of,

an expansible outer form mounted on a generally at 5 frame;

said expansible form of two symmetrical parts of generally L-shaped congurations;

an outwardly extending flange on the upper and lower edges of each of said two symmetrical form sections; plurality of locator pins extending upwardly from said flat frame;

a plurality of openings in said lower ilange, said openexpansion of said outer form permits the release of a finished concrete casting;

at each of the two diagonally opposite corners of the outer form are fitted with a pair of interengaged bevel gears carried on a threaded shaft, a iixed nut on each of the respective L-shaped members; each bevel gear when rotated acting to expand said corners by means of said threaded shaft operating `against said fixed nut on each of the respsective L-shaped members, said expansion taking place at a uniform rate, stoppage of said rotation forming an etective clamp to limit and prevent the accidental displacement of either of the form sections.

References Cited by the Examiner UNITED STATES PATENTS 457,886 8/91 Landis 25-131 761,727 6/04 Tiiany .Z5-41.2

896,330 8/08 Scheelky 25-118 1,142,887 6/15 Keenan 25--131 1,143,697 6/15 Gallant et al. 25-131 1,529,079 3/25 Nelson 25--121 1,754,484 4/30 Pelton 25-120 2,068,302 1/37 Nickol 25-130 2,827,683 3/58 Bernart et al. 25-130 2,828,526 4/58 Blasius et al. 25-130 2,903,777 9/59 Mitchell 25-130 I. SPENCER OVERI-IOLSER, Primary Examiner.

ROBERT F. WHITE, MICHAEL V. BRINDISI,

Examiners. 

